Ordnance Survey's Levelling of Great Britain |
[1GL, 2GL Abstract] [1GL, 2GL Transcription] |
[Timeline] [FBM List] |
Files Held at Kew'Levelling' Files | [General Levelling Files - 1GL - 2GL] (All | Viewed) |
Ref | Source | Date | Notes |
---|---|---|---|
+ - OS 45 | Ordnance Survey of Great Britain: Director General: Manuals and Instructions | 1882-1978 | |
OS 45/82 | Levelling handbook: 2nd edition | 1963-1974 |